Self-locking electric outlet and plug



Aug. 24, 1948. c H, R 2,447,597

SELF-LOCKING ELECTRIC OUTLET AND PLUG Filed Aug. 28, 1945 FlG. 1 FIG. 2

I I 1a 1,6 1 [5/ v FIG. 4

INVENTOR CHARLES H. REED,

ATTORNEYS Patented Aug. 24, 1948 SELF-LOCKING ELECTRIC OUTLET AND PLUG Charles H. Reed, Fort Stanton, N. Mex.

Application August 28, 1945, Serial No. 613,108

This invention relates to improvements in electrical connectors, and more particularly to an electrical outlet and plug assembly wherein means is provided for separably locking the plugs in their receptacles.

A main object of the invention is to provide a novel and improved electrical device of the above indicated character, and having means cooperating with the outlet structure for automatically locking the plugs with their prongs in contact 9 Claims. (01. 173-330) with the electrical conductor elements of said outlet structure.

A further object of the invention is to provide improved automatic locking means for securing electric plugs in convenience outlets, said locking means being simple in construction and providing positive securement of the plug terminals in electrical contact with bus bar elements carried by the outlets.

Further objects and advantages of theinvention will appear from the following description, and the accompanying drawings, wherein:

Figure 1 is a front view of an electrical outlet constructed in accordance with this invention.

Figure 2 is a side elevational view, partly in section, of the outlet of Figure 1 with electrical plugs positioned therein.

Figure 3 is a top view, partly in section, of the outlet of Figure 1.

Figure 4 is a rear elevation of the outlet of Figure 1.

Referring to the drawings, Ii designates the receptacle element of the connector assembly, here shown as a wall plate I l of Bakelite or other plastic insulating material, and may be of rectangular or other suitable shape. The plate II is formed with a plurality of transversely extending rear rib members l2 to whose opposite ends vertical bus bars l3, l3 are secured, said rear rib members l2 being formed to support said bus bars in rearwardly convergent relationship, as shown in Figure 3. Substantially aligned with the facing inner surfaces of the bus bars [3, l3, are pairs of openings l4, l4 adapted to receive the prongs I! of ordinary electric plugs l9, and guide them into contact with the facing surfaces of the bus bars I3, l3. The positions of bus bars [3, l3 are such that the prongs of an ordinary electrical plug will engage between them with a slight wedging action so assuring good electrical contact therewith.

Each bus bar I3 is formed on its forward edge with a laterally inwardly projecting transverse lower lug l5 and on its rear edge with a laterally inwardly projecting upper lug I5, these lugs being positioned, at the lower and upper ends, respectively, of each opening M. The vertical spacing of lugs l5 and I6 is slightly less than the height of a standard plug prong ll of a standard plug l9, such as shown in Figure 2. p The front surface of wall plate II is, formed in the region of each pair of slots M with a concave semi-circular recess l8 so formed that after engagement with the plate surface an ordinary plug l9 may be rearwardly and downwardly tilted, as shown in Figure 2.

While a standard plug I9 may be used with the receptacle plate II, it will be held therein only by gravity and by frictional contact with the bus bar members l3, l3. In accordance with the present invention a novel plug 22, having a body similar to the standard plug 19, and prongs 24 generally similar to the standard prongs l1, have rounded ends as indicated at 25 and have their upper and lower edges cut away to define upper and lower shoulders 20, 20, either of which may be engaged behind the related upper prong retaining lugs N5 of the bus bars l3, as shown in Figure 2, so that the plug 22 is locked in place.

As shown in Figure 2, the upper ends of the slots M are required to be forwardly inclined, as indicated at 23 in order to permit the prongs of an ordinary plug H! to pass through the slots at a downward angle in order, to engage between the related upper and lower retaining lugs l6 and I5.

However, in the case of the novel plug 22 the prongs 24 can be inserted through the slots l4 and forcibly engaged between the retaining lugs l6 and I5 in an inclined position, the rounded ends 25 acting to cam the retaining lugs aside sufficiently before seating behind the shoulders 20 to permit the body of the plug 22 to subside to engage flush with the face of the plate ll, instead of remaining in the inclined or tilted position required of the ordinary plug [9. Removal of both types of plugs from the wall plate II is accomplished by reversal of the above described connecting manipulation.

While a specific embodiment of the invention has been disclosed herein, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is not intended that the disclosure limit the invention except as defined by the scope of the appended claims.

What is claimed is:

1. An electrical connector assembly comprising a receptacle consisting of an insulated plate formed with pairs of aligned slots, a pair of bus bars mounted on the back of the plate and extending in alignment with said slots, each bus bar having a set of retaining lugs for each slot aligned therewith, each set consisting of an upper lug and a lower lug, said upper retaining lug of each set being spaced rearwardly from the related lower lug, and a plug consisting of a body having a pair of prongs projecting therefrom in position for insertion and withdrawal through any of said pairs of slots, the vertical width ofthe. prongs being such as to require said prongs to beinserted through said slots at a downward and rearward inclination with respect to said plate to enable said prongs to be passed between the. related upper and lower retaining lugs: and thereby electrically and frictionally engaged therebetween.

2. An electrical connector assembly comprising a receptacle consisting of any insulated plate formed with pairs of aligned slots; a pair of' bus bars mounted on the back of the plate and extending in alignment with said slots, each bus bar having a set of retaining lugs for each: slot alignedtherewitheach set consisting of an upper lugv and a lower lug, said upper retaining lugof each set being spaced rearwardly from. the related lower lug, and a plugconsisting. of. abody having a pair of prongs projecting therefrom in position for insertion and: withdrawal. through any of said pairs of slots, the vertical width of. the prongs. being. such as to require said prongs to be inserted through said slots. at. a downward and rearward inclination with respect to said plateto enable. said. prongs to bepassedbetween the related upper and lower retaining lugsv and. thereby electrically and frictionally engaged therebetween,.said bus bars having their facing surfaces converged rearwardly away from. said plate and positionedto be engaged. by the. plug prongsas said prongs-comeinto engagement with said retaining. lugs. whereby said prongs have wedging engagement with. thefacing surfaces i said bus bars.

3,. An electrical. connector assembly comprising a. receptacle. and a. plug, said receptacleconsisting of, an insulated plate having a. pair of parallel bus bars secured to thebackthereof, slotsformed in said plate. and spaced along. and in alignment with. said bus bars, said slots being. transversely aligned. in pairs, a-set of retaining lugs on each bus bar. for. each. of. said slot-s. each set consisting of tanupper lug and a lower lug spaced forwardly and downwardly from said upper lug, said. plug consisting of abody having a pa r of prongs-projecting-therefromand arranged for free insertion and. withdrawal through. any pair of said slots, and shoulders on. the-upper and lower edges of said prongs whereby at least one of. said shoulders is engageable behind one of said retaining lugs for retaining said plug assembled with said plate as said plug prongs are inserted in the related slots and-passed into engagement between the'related upper and lower retaining lugs.

4; Anelectrical connector assembly comprising a receptacle and a plug, saidreceptacleconsisting of. an insulated plate havinga pair of parallel bus bars secured to the back thereof, slots formed in said plate and spaced-along and in alignment with said bus bars,.said.slotsbeing. transversely aligned in pairs, .a set of retaininglugs oneachbus bar. for eachofsaid-slotseach set consisting of anupper. lug and a lower lug spacedforwardly andldownwardly from said upper lug, said plug. consisting ot a. body having. a pairof. prongs. projecting therefrom andarranged. for. free insertion and withdrawal. through: anypair. of: said slots, and. shoulders, oncthe.- upper. and lower edges] of. said- 4 prongs whereby at least one of said shoulders is engageable behind one of said retaining lugs for retaining said plug assembled with said plate as said plug prongs are inserted in the related slots and pased into engagement between the related upper and lower retaining lugs, said upper and lower retaining lugs of each set being vertically and rearwardly spaced from each other at distancesrequiring insertion. of said plug prongs therebetween at a downward and rearward angle with respect to said plate.

'5. An electrical connector assembly comprising areceptacle anda plug, said receptacle consisting of'ian insulated plate having a pair of parallel bus bars secured to the back thereof, slots formed in said. plate and spaced along and in alignment with said bus. bars, said slots being transversely aligned in pairs, a set of retaining lugs on each bus bar for each of said slots, each set consisting of an upper lug and a lower lug spaced forwardly and downwardly from. said. upper lug, said plug consisting of. a. body having a pair of prongs projecting therefromand arranged forffree insertion and Withdrawal. through any pair of said slots, and shoulders on the upper and lower edges of said prongswhereby at leastone of. said shoulders is engageable behind oneof said retaining lugs for retaining. said plug. assembled with said plate as said plug prongs are. inserted in, the related slots and passed'into engagement between the related upper: and. lower retaining lugs, said upper and lower retaining lugs of each set being vertically and. rearwardly spaced from each other at distances requiring insertion of said plug prongs therebetween ata downward and rearward angle with. respect to said plate,v said plug being arranged. to be tilted downwardly and forwardly from its inclined position following insertion of the plug prongs between said upper and lower retaining lugs in a manner to positively engage, the shoulders on the upper edges of the plug prongs behindisaid. upper retaining lugs and thereby positively .locksaid plug in assembled relation to said receptacle.

6. An electrical connector assembly comprising a receptacle and a plug, said receptacle consisting of an insulated plate havingapair of parallel bus bars secured to the back thereof, slots formed in said plate and spaced along and inalignment with said bus bars, said slots being transversely aligned in pairs, a set of retaining lugs on each bus bar ioreach of said slots, each set consisting ofanupper lug and a lower lug spaced forwardly andi downwardly from said upper lug, said plug consistingof a body having. a. pair of prong-s projecting. therefrom. and arrangedfor free insertion and withdrawal through any pair of said slots, and shoulders on the upper and lower edges of said prongs whereby at least one of said shoulders is engageable behind one of said retaining lugs for retaining. said plug. assembled with said plate a said plug prongs are inserted in the related. slots: andjpassedinto engagement between the related upper and lower. retaining lugs, the iacingtsurfaces. of. said bus bars converging rearwardly, whereby the plugsv have wedging engage.- ment. therewith as the prongs are inserted between the related sets of. retaining lugs.

7.. Anelectrical connector. assembly comprising areceptacle. and a plug, said receptacle being formed with a slot and'having a bus bar. secured to. its back. along said slot, said bus bar having a pair of vertically spaced retaining lugs, said retaining lugs. being spaced with respect to each other. at. difierent distances vfrom the back of said receptacle, said plug comprising a body having 9, prong projecting therefrom for insertion and removal through said slot, the upper edge of said prong being formed with a shoulder, said plug being arranged to be manipulated to insert said prong through said slot at a downward and rearward inclination and pass said prong between said retaining lugs and then tilted in a forward and downward direction so as to engage said shoulder behind said uppermost retaining lug and thereby positively lock said plug in assembled relaticn to said receptacle.

8. An electrical connector assembly comprising a receptacle and a plug, said receptacle being formed with a slot and having a bus bar secured to its back along said slot, said bus bar having a pair of vertically spaced retaining lugs, said retaining lugs being spaced with respect to each other at different distances from the back of said receptacle, said plug comprising a body having a prong projecting therefrom for insertion and removal through said slot, the upper edge of said prong being formed with a shoulder, said plug being arranged to be manipulated to insert said prong through said slot at a downward and rearward inclination and pass said prong between said retaining lugs and then tilted in a forward and downward direction so as to engage said shoulder behind said uppermost retaining lug and thereby positively lock said plug in assembled relation to said receptacle, said upper and lower lugs being vertically spaced at a distance to produce supporting engagement of the lower lug with the lower edge of the plug prong so as to positively maintain said shoulder behind and in engagement with the upper lug while said plug is in said forwardly and downwardly tilted position.

9. An electrical connector assembly comprising a plug having a pair of contact prongs extending therefrom, shoulders on the edges of each of said prongs adjacent the end thereof, a receptacle comprising a faceplate formed with a pair of slots positioned to receive said prongs, buss bar-s mounted on the back surface of said faceplate, retaining lugs on said buss bars positioned relative to said slots and between which said prongs can be passed and withdrawn with said plug in an inclined position with respect to said faceplate, said shoulders being arranged on said prongs so that at least one of said shoulder-s can engage behind one of said retaining lugs and said plug moved from the inclined position to a position flush with the said faceplate so as to positively engage the shoulder behind the retaining lug and thereby lock said plug in position on said faceplate.

. CHARLES H. REED.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

